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331 hemi mystery cam


bostonhemi
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Hello fellow car enthusists. I purchased a 331 chrysler hemi short block project that went through a couple of owners and cannot find any specs or brand on my camshaft. The only numbers on the cam are F.194 and P 7745. The block is a 1956 industrial and the cam was modified on the front for a small cover. Any help would be appreciated. ty<!-- google_ad_section_end -->

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If you want to find out the specs of the cam, that's easy enough to do, but will take an hour or so.

First, purchase a "degree wheel" and a dial indicator with a magnetic base. You'll also need a valve lifter and pushrod. You can find the degree wheels from many engine parts companies, I believe. I think I got mine from Mr. Gasket, or similar. Plus, you'll also need for the cam to be in the block and a timing chain set to move it (with the cam correctly indexed to the crankshaft).

Then, with a socket on the front of the crankshaft (another item from the race engine builders), you can then turn the engine until you can determine Top Dead Center on #1 cylinder. Then, with a flexible wire, position the degree wheel and pointer to "0". Then oil and install the lifter and pushrod, with the dial indicator mounted on the cylinder deck and using the pushrod to work it (which can be a little tricky to get things aligned and then maintained that way).

From there, rotate the crankshaft slowly to see where valve lift begins, maximizes, and lift ends for the intake and exhaust valves on #1 cylinder. Note each of these significant points on a piece of paper. Also, SAE specs call for measuring lift at .006" lift rather than where the lift really starts . . . this is the "ramp" and isn't a part of the main lobe, especially on mechanical lifter cams. You can also use the hot rod industry's "standard" of .050" lift to check the duration with, too.

So, once you determine which lobe is Intake and Exhaust, roll the crankshaft over and watch the dial indicator's needle. When lift starts, then notice when .006" is reached (note the degrees before TDC) and also .050", then proceed to max lift (noting that amount in inches), and finally to the .050" and .006" positions on the closing side of the lobe. You might need to repeat this a few times to make sure the readings are consistent, for good measure.

Then, take the duration figures and add "180" to them, for the official duration. Lobe lift figures will need to be multiplied by the rocker arm ratio to get total valve lift. Then, you can check some of the various manufacturers (even Chrysler?) to see what looks close.

"Industrial" engines could come in several versions, I believe, depending upon where they ended up. Some might be car or light truck-spec engines designed for constant rpm use (think irrigation pump motors), or they might be for a normal water craft, or the Industrial Division could have built some "special purpose" enginges (i.e., race car). Might even have been in a school bus! But with the somewhat unknown origin of the engine, anything's possible . . . which is why doing the checks of the lobe specs can be important. Other thing would be if the cam is a hydraulic lifter cam or a solid lifter cam!!!

There's also a shop that specializes in the Early Hemis . . . . Hot Heads. Hot Heads Research & Racing Early Chrysler Hemi Home, plus Early Hemi Engines looks like it might have some additional information for ID of various items.

Just some thoughts . . .

NTX5467

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Guest Bob Call

Unless this engine has adjustable rocker arms and rocker coovers with bumps for exhaust rocker clearence it originally had a hydralic cam and lifters. Some industrial, marine and truck had adjustable rockers and solid lifters.

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